1. Field
Example embodiments relate to an ink discharge device that discharges uniform amounts of ink droplets from an inkjet head, and a control method thereof.
2. Description of the Related Art
An inkjet printing apparatus is an apparatus which prints an image in a designated color by discharging fine droplets of an ink for printing at a desired position of a printing medium. The inkjet printing apparatus includes an inkjet head having a plurality of nozzles to discharge the ink droplets.
In order to manufacture an LCD panel of a superior quality in a printing process using the inkjet head, respective pixels of the LCD panel must have a uniform color value. Such a uniform color value may be obtained by adjusting an amount of ink droplets filling the respective pixels. That is, it is of relative importance in manufacture of the LCD panel having an excellent quality to uniformly adjust the amount of ink droplets discharged from the inkjet head.
Generally, when color values of the respective pixels printed by applying an equal voltage to the respective nozzles of the inkjet head are measured, the color values of the respective pixels are different such that an inspector can make out the difference with the naked eye. That is, although the equal voltage is applied to the nozzles of the inkjet head, the nozzles may not discharge an equal amount of ink droplets due to characteristics of the respective nozzles. Therefore, voltage applied to each of the nozzles is varied so as to discharge a uniform amount of droplets from the nozzles. This process is referred to as a Driver per Nozzle (DPN) process. During a conventional DPN process, feedback of substantially printed color values is required to control applied voltage. It takes a relatively long time to receive such a feedback. Further, due to characteristics of the respective nozzles, the equal color value is not always obtained under equal voltage and there are noise components. In order to calculate voltages applied to the respective nozzles according to the noise components, multiple-order printing and feedback of printed color values is required. Thereby, it takes a relatively long time to discharge uniform amounts of ink droplets discharged from a plurality of nozzles having different characteristics.